What is 2¹⁵, and what limit does it mark?

32768 — the number of non-negative values in a signed 16-bit integer, whose range is −32768…32767.

Chunk 32768 → 32 · 76 · 8 → moon · cage · ivy: the moon locked in a cage overgrown with ivy. A signed 16-bit short maxes out at +32767 because one of its 65536 values is spent on the sign; 2¹⁵ = 32768 is that halfway mark.